As Breck has indicated, your trigger cannot generate a result set - you need to consume the result set generated by the procedure call so that it does not propagate from the trigger into the statement context that caused the trigger to be called.

For example:

SELECT*INTO#tempFROM"dba"."push_dcn"("reqid"='100',"msgid"=2221);

This stores the result set from the call to push_dcn into the (automatically generated) temporary table #temp.

ahh, i see - thanks!
in the meantime i read the above mentioned artice: http://www.sybase.com/detail?id=1093467 where it is done like this:
SET xmlResult = (SELECT C2 From sp_GetQuoteYahoo() with (C1 long varchar,C2 long varchar) WHERE C1 = 'Body');